State estimation processor and state estimation system

ABSTRACT

A microprocessor unit (MPU) connected to external sensors is provided with an interface unit that acquires detection information acquired by the external sensors and a digital signal processor (DSP) that estimates the state of a target object on the basis of the detection information acquired by the interface part and generates state information. The DSP is provided with a SIMD type arithmetic processing circuitry that processes a plurality of information with one command and is provided with single precision floating point computing units. The interface part outputs the state information generated by the DSP to an externally provided main processor. Therefore, power consumption can be reduced.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to techniques for estimating a state of anobject in a terminal device etc. In particular, the present inventionrelates to techniques for reducing the power consumption of the terminaldevice when estimating the state of the object.

Description of the Background Art

Conventionally, a technique to incorporate a sensor in a terminal deviceis known. In the known technique, the behavior state of the user havingthe terminal device and the state of the terminal device are estimatedbased on a value detected by the sensor. As an applicable field of suchtechnology, PDR (Pedestrian Dead Reckoning) and the like are known(Japanese Patent No. 4243684), for example.

However, in the application to take some kind of actions whileestimating the state of an object, it is necessary to always continueobserving the object. Therefore, the sensor which detects the observedvalue used as the foundation for estimating the state always has thesituation that it must continue working. And the processor whichprocesses the observed value always acquired by the sensor also had tocontinue working, without resting, and had the problem that powerconsumption increased. Especially, in the carried terminal device, apower supply is limited to a battery charger, the request to reduce ofpower consumption has a high level.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide techniques toestimate a state of an object while controlling power consumption.

Thus, the present invention is directed to a state estimation processor.

According to an aspect of the present invention, the state estimationprocessor connected to an external detection device and an externalcomputer comprises: an interface circuitry configured to obtaindetection information obtained by the external detection device andoutput state information to the external computer; and a calculatingcircuitry including a SIMD (Single Instruction Multiple Data) typearithmetic processing circuitry processes a plurality of information byone command and provided with a single precision floating pointcomputing unit; the calculating circuitry configured to: estimate astate of an object based on the detection information obtained by theinterface circuitry; and generate the state information according to thestate of the object.

The present invention is also directed to a state estimation system.

According to an aspect of the present invention, the state estimationsystem comprises: a detection device obtains detection information; amain processor works in first operation mode, and second operation modein which power consumption is smaller than the first operation mode; anda state estimation processor connected to the detection device and themain processor; wherein the state estimation processor, including: aninterface circuitry configured to obtain detection information obtainedby the detection device and output state information to the mainprocessor; and a calculating circuitry including a SIMD type arithmeticprocessing circuitry processes a plurality of information with onecommand and provided with a single precision floating point computingunit; the calculating circuitry configured to: estimate a state of anobject based on the detection information obtained by the interfacecircuitry; and generate the state information according to the state ofthe object; the main processor configured to: shift to the firstoperation mode base on a timing which the state information is inputfrom the interface circuitry; generate output information during thefirst operation mode based on the state information generated by thestate estimation processor.

These and other objects, features, aspects and advantages of the presentinvention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a state estimation system.

FIG. 2 is a schematic view showing the circuit configuration of a DSP.

FIG. 3 is a conception diagram showing the data which the DSP processes.

FIG. 4 shows the figure which compared the case where sequentialprocessing of the 12-axes information was carried out with the casewhere a DSP processes the 12-axes information.

FIG. 5 is a flow chart showing operation of the MPU.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed description of preferred embodiments of the presentinvention is made below, referring to the accompanying drawings. Itshould be noted that the descriptions related to a direction or anorientation correspond to the drawings for the convenience ofdescription unless otherwise specified, but do not limit products,merchandized products, and the scope of the invention, for example.

The present application claims priority from Japanese Application Number2014-071782 filed in Japan on Mar. 31, 2014, the contents of which areincorporated herein by reference.

FIG. 1 shows a state estimation system 1. The state estimation system 1includes one or more sensor 2, a MPU (Micro-Processing Unit) 3 and a CPU4.

In the following descriptions, the state estimation system 1 isdescribed as what is incorporated in the portable terminal device (forexample, a smart phone, a mobile phone and PDA, etc.) carried by a user.

The sensor 2 is a detection device which detects the information aboutthe surrounding environment and a motion for example, and generates thedetection information 10. A temperature sensor, a humidity sensor, anilluminance sensor, an air pressure sensor, a contact sensor, anacceleration sensor, a gyro sensor, or a magnetic sensor is assumed asthe sensor. However, the sensor 2 is not limited to these. The stateestimation system 1 must not be provided with all the sensors enumeratedhere, either.

In the following descriptions, a user who carries the portable terminaldevice is considered to be an object. And the state estimation system 1shall generate output information 12 by estimating the state (condition,action) of the user. Therefore, the sensor 2 in the preferred embodimentis described as a structure including an acceleration sensor, a gyrosensor, and a magnetic sensor, in order to detect physical quantityrequired in order to estimate the user's action. As the user's actionestimated, a walking condition, a state of rest, a talking state, aninspection state, or a riding state is assumed, for example.

Each sensor 2 is connected all to the MPU 3 to show it in FIG. 1. Andthe detection information 10 obtained by each sensor 2 is outputtedtowards the MPU 3.

The MPU 3 is provided with a DSP (Digital Signal Processor) 30, a RAM31, a timer 32, and an interface part 33.

The DSP 30 is an arithmetic circuit which reads a command stored in theRAM 31 and operates according to the command. In the preferredembodiment, the command executed in the DSP 30 is expressed as 64-bitdata constituted so that it might correspond to three parallel VLIW(Very Long Instruction Word). Therefore, the DSP 30 can execute threeactual instructions in one cycle (The details are mentioned below.). Thecommand shall be analyzed by the decoder (not shown) and shall bewritten in the RAM 31.

The DSP 30 reads the value of each sensor 2 according to the interruptsignal (hereinafter, referred to as a “detection timing signal”) inputfrom the timer 32. That is, the DSP 30 has the function to obtain thedetection information 10 obtained by the sensor 2 through the interfacepart 33, and to store it in the RAM 31.

The DSP 30 estimates the state of the object based on the detectioninformation 10 stored in the RAM 31 and generates the state information11. The details of the DSP 30 are mentioned below.

The RAM 31 is a storage device used as working area of the DSP 30, andit is used in order to memorize various information. For example, theRAM 31 memorizes the state information 11 generated by the DSP 30. Inaddition, the RAM 31 also memorizes the detection information 10 (notshown in FIG. 1) obtained from each sensor 2.

For simplifies, FIG. 1 shows the RAM 31 as if it was a single structure.However, the RAM 31 is usually formed by a plurality of types of storagedevices. In addition, the information read from the RAM 31 isillustrated in FIG. 1 so as to pass through the DSP 30 by all means. Butthe RAM 31 is provided with the storage area (storage device) which canbe referred by the CPU 4, and the CPU 4 is constructed to be able toread desired information from the RAM 31 without relaying the DSP 30.

The timer 32 generates a detection timing signal periodically (in thepreferred embodiment 100 [Hz]), and outputs it to the DSP 30 via theinterface part 33. As already describe, when the detection timing signalis received, the DSP 30 reads the value of each sensor 2 and stores itin the RAM 31 as the detection information 10.

The interface part 33 is connected with each sensor 2. As shown in FIG.1, the sensor 2 is connected to the MPU 3 by the parallel state or theserial state. The interface part 33 is connected with the CPU 4. Thus,the interface part 33 has a function to connect the MPU 3 and eachsensor 2, and a function to connect the MPU 3 and the CPU 4. Therefore,the interface part 33 has a function which obtains the detectioninformation 10 obtained by the sensor 2, and a function which outputs tothe CPU 4 the state information 11 generated by the DSP 30.

Thus, the MPU 3 has a function which generates the state information 11based on the detection information 10 obtained by the sensor 2, and afunction which outputs the detection information 10 towards the CPU 4.That is, the MPU 3 is equivalent to the state estimation processor inthe present invention. The details of the MPU 3 are mentioned below.

The CPU 4 functions as a main processor in portable terminal device.Although omitted for details, storage devices, operating parts (e.g.,keys and buttons), a display part (e.g., a liquid crystal display), aloudspeaker which outputs a sound, a microphone which converts a soundto an electrical signal, the communications unit which communicatesbetween external devices, and the like are connected to the CPU 4 asappropriate.

The CPU 4 executes a program stored in the storage device (not shown)while reading it, thereby performing calculation of various types ofdata, creation of control signals, and the like. Thus, the CPU 4 has afunction of controlling other composition with which the MPU 3 and theportable terminal device, and a function of calculating and creatingvarious types of data.

The CPU 4 outputs a DSP wake-up signal to the MPU 3 according topredetermined applications (for example, course guidance applicationetc.) having been started. On the contrary, according to the timingwhich ends predetermined application, the CPU 4 outputs a DSP reducingsignal to the MPU 3. The CPU 4 generates the output information 12 basedon the state information 11 input from the MPU 3. The CPU 4 provides theoutput information 12 for the user by outputting the output information12 to the display part (not shown).

The CPU 4 has CPU normal operation mode. And the CPU 4 also has CPUreducing operation mode in which power consumption is smaller than theCPU normal operation mode. The CPU reducing operation mode isoperational mode what is called “a sleep mode” for example, and the CPUreducing operation mode is operational mode in which only somerestricted circuits in CPU 4 are working.

In the CPU 4, operational mode changes from the CPU reducing operationmode to the CPU normal operation mode according to the CPU wake-upsignal outputted from the MPU 3. In the CPU 4, operational mode changesfrom the CPU normal operation mode to the CPU reducing operation modeaccording to the CPU reducing signal outputted from the MPU 3. However,even if it is a case where the CPU reducing signal is received from theMPU 3, when other applications are being performed, the CPU 4 does notshift to the CPU reducing operation mode.

FIG. 2 is a schematic view showing the circuit configuration of the DSP30. The DSP 30 is provided with a load-store unit 300, two registers 301and 302, two arithmetic logic units 303 and 304, four single precisionfloating point computing units 305, and a switching section 306 as shownin FIG. 2.

The load-store unit 300 reads data from the RAM 31, and stores it to theregister 301 and 302. The load-store unit 300 stores data stored in theregister 301 and 302 to the RAM 31. The load-store unit 300 sets thecommand (the command read from RAM 31) to the arithmetic logic units 303and 304. When the value stored in the register 301 is a pointer value,the load-store unit 300 has a function to specify the data stored in theRAM 31 according to the pointer value, and a function to read it.

The registers 301 and 302 are storage device which store datatemporarily. The data read from the RAM 31, the value calculated by thearithmetic logic units 303 and 304, and the like are stored in theregisters 301 and 302.

The arithmetic logic unit 303 is an integer-arithmetic logic unit whichperforms a predetermined operation to the data stored in the register301 according to the command input from the load-store unit 300. Thevalue calculated by the arithmetic logic unit 303 is stored in theregister 301. For example, the arithmetic logic unit 303 is used inorder to calculate the pointer value for reading desired data from theRAM 31.

The arithmetic logic unit 304 is constituted as a SIMD (SingleInstruction Multiple Data) type computing unit provided with the foursingle precision floating point computing units 305. The arithmeticlogic unit 304 can execute one command in parallel to the data (namely,a plurality of data) set to each of the four single precision floatingpoint computing units 305 (in 1 cycle). The value calculated by thearithmetic logic unit 304 is stored in the register 302, and is storedin the RAM 31 by the load-store unit 300.

The switching section 306 has a function to switch operational mode ofthe DSP 30 between first operational mode and the second operationalmode in which power consumption is smaller than the first operationalmode. In other words, the DSP 30 has two operational mode. One is DSPnormal operation mode. Another is DSP reducing operation mode in whichpower consumption is smaller than the DSP normal operation mode.

According to the DSP reducing signal input from the interface part 33,the switching section 306 switches the DSP normal operation mode of theDSP 30 to the DSP reducing operation mode. The DSP reducing signal isinput via the interface part 33 from the sensors 2 (It is not limited toall sensors) or the CPU 4 as an interrupt signal. The DSP 30 may changeoneself to the DSP reducing operation mode.

According to the DSP wake-up signal input from the interface part 33,the switching section 306 switches the DSP reducing operation mode ofthe DSP 30 to the DSP normal operation mode. The DSP wake-up signal isinput via the interface part 33 from the sensors 2 (It is not limited toall sensors) or the CPU 4 as an interrupt signal. The detection timingsignal from the timer 32 may also function as the DSP wake-up signal.

FIG. 2 illustrates it as if the control object of the switching section306 is only the load-store unit 300. However, this is simplification fordrawing FIG. 2. The switching section 306 is able to perform switchingcontrol for any constitution (circuit) that the DSP 30 includes.

The above is the description of the structure and functions of the stateestimation system 1. Next, the structure of the operation (operationarchitecture) by the DSP 30 is described. The DSP 30 performs dataprocessing (processing to acquire the state information 11) to thedetection information 10 not in the DSP reducing operation mode but inthe DSP normal operation mode.

FIG. 3 is a conception diagram showing the data which the DSP 30processes.

In the following description, a motion of the portable terminal devicewith which the state estimation system 1 is incorporated is observed.And the case where the action of the user possessing the portableterminal device is estimated is described, for an example.

“A”, “B”, “C”, and “D” which are shown in FIG. 3 show a mass of data.For example, in the case where “A” is an output of the 3-axisacceleration sensor, “Ax” is a value of X-axis component ofacceleration, “Ay” is a value of Y-axis component of acceleration, and“Az” is a value of Z-axis component of acceleration. In the case where“B” is an output of the 3-axis gyro sensor, “Bx” is a value of X-axiscomponent of angular velocity, “By” is a value of Y-axis component ofangular velocity, and “Bz” is a value of Z-axis component of angularvelocity. In the case where “C” is an output of the 3-axis magneticsensor, “Cx” is a value of X-axis component of magnetic vector, “Cy” isa value of Y-axis component of magnetic vector, and “Cz” is a value ofZ-axis component of magnetic vector. In the case where “D” is thecorrection value of the bias of the 3-axis gyro sensor, “Dx” is thecorrection value of X-axis component of angular velocity, “Dy” is thecorrection value of Y-axis component of angular velocity, and “Dz” isthe correction value of Z-axis component of angular velocity.

The correction value of the bias of the gyro sensor is not the detectioninformation 10 obtained from the sensor 2 directly. Since the techniqueof calculating the correction value of the bias of the gyro sensor canapply various technology proposed from the former, it omits a specificdescription here.

Thus, when observing a motion of portable terminal device and estimatinga state, it is common that 12-axes information will be processed asmentioned above. However, it becomes 9-axes in estimating a state forexample, without adopting the value of the magnetic sensor. That is, forstate estimation, it does not necessarily become an indispensablecondition to process 12-axes information, and it is changed asappropriate according to the demand of application.

The DSP 30 divides 12-axes information into alpha0, alpha1, alpha2,alpha3, beta0, beta1, beta2, beta3, gamma0, gamma1, gamma2 and gamma3,and processes it.

FIG. 4 shows the figure which compared the case where sequentialprocessing of the 12-axes information is carried out with the case wherethe DSP 30 processes the 12-axes information. In FIG. 4, the minutedescription about a detailed operation is omitted, and processing isshown as a conception diagram so that it may be easy to understand thecharacteristics in the DSP 30.

In the case of sequential processing, as shown in the left table of FIG.4, the data of alpha 0 (Ax) is processed, after loading from the RAM 31during the first cycle, calculating a pointer during the second cyclefor the next data and multiplying during the third cycle, it becomes theflow of storing a result in the RAM 31 during the fourth cycle.Therefore, 48 cycles is needed in order to complete processing about all12-axes information.

On the other hand, in the DSP 30, the instruction set corresponds tothree parallel VLIW. Therefore, the DSP 30 can execute three actualinstructions in one cycle. As already described, the arithmetic logicunit 304 is the SIMD type computing unit, and is provided with the foursingle precision floating point computing units 305 as an executionunit. Therefore, the DSP 30 can execute one command (for example,multiply operation) to four data in the arithmetic logic unit 304 by onecycle.

Therefore, as shown in the right table of FIG. 4, alpha (alpha0, alpha1,alpha2, alpha3) is read in a first cycle. In a second cycle, beta(beta0, beta1, beta2, beta3) is read and a pointer is calculated by thearithmetic logic unit 303. In a third cycle, gamma (gamma0, gamma1,gamma2, gamma3) is read, a pointer is calculated by the arithmetic logicunit 303, and multiplication of alpha (alpha0, alpha1, alpha2, alpha3)is executed by the arithmetic logic unit 304. Further, in the fourthcycle, alpha (alpha0, alpha1, alpha2, alpha3) is written in the RAM 31,a pointer is calculated by the arithmetic logic unit 303, andmultiplication of beta (beta0, beta1, beta2, beta3) is executed by thearithmetic logic unit 304.

Thus, for detection information 10 to be provided by one observation,the DSP 30 can complete processing at six cycles. Therefore, comparedwith the case where sequential processing is carried out by main CPUlike before, the clock frequency of the MPU 3 (the DSP 30) can belowered.

Therefore, the DSP 30 can reduce power consumption compared with theconventional microcomputer. In a common microcomputer, although theclock frequency of around 80 [MHz] is required for such processing, theDSP 30 in the preferred embodiment can be processed by around 7 [MHz].

In the circuit structure of computing unit, there are thecharacteristics that a floating point arithmetic machine has small sizecompared with a fixed-point arithmetic machine, generally. However, in acalculation with a floating point arithmetic machine, the position of adecimal point must be determined, calculation depth becomes deep.Therefore, in a calculation with a floating point arithmetic machine,the additional circuit is independently needed. That is, there is asituation that the circuit structure as the whole became small as aresult in the direction at the time of adopting a fixed-point arithmeticmachine. Therefore, in a general microcomputer, not a floating pointarithmetic machine but a fixed-point arithmetic machine is used in manycases.

However, such an additional circuit is composed of the minimum in theuse of processing the detection information 10 from the sensor 2 andestimating a state. Therefore, the DSP 30 makes circuit structure smallby adopting the single precision floating point computing unit 305compared with the case where a fixed-point arithmetic machine isadopted.

Particularly, the Kalman filter used for sensor fusion has acharacteristic that the dynamic range of the parameter is wide.Therefore, it is necessary to prepare for a 64-bits operation device tomaintain operation precision at the same level as the single precisionfloating point computing unit 305 (16 bits) using a fixed-pointarithmetic machine, and a circuit structure enlarges. That is, when theDSP 30 performs the operation using the Kalman filter, the effect whichadopts the single precision floating point computing unit 305 becomesmore remarkable.

Next, a method for controlling the sensor 2, the MPU 3, and the CPU 4 inthe state estimation system 1 is described.

FIG. 5 is a flow chart showing operation of the MPU 3. When a powersupply is put into the state estimation system 1 (the portable terminaldevice), the MPU 3 becomes waiting state after having carried outpredetermined initial setting. The waiting state is either of the DSPnormal operation mode or the DSP reducing operation mode.

In the waiting state, the MPU 3 is placed in a state in which itmonitors reception of the DSP reducing signal (Step S1), arrival of adetection timing (Step S5), reception of the DSP wake-up signal (StepS11), and arrival of a operation timing (Step S15).

In the waiting state, when the DSP reducing signal is received, the MPU3 gives Yes as the result in the decision in Step S1, and it identifiesan origin of the transmission of the DSP reducing signal.

When the origin of the transmission of the DSP reducing signal is theCPU 4 (Yes in Step S2), the MPU 3 suspends the sensor 2 (Step S3). Andthe switching section 306 switches operational mode of the DSP 30 to theDSP reducing operation mode (Step S4).

Thus, when Step S4 is executed, henceforth, the DSP 30 becomes the DSPreducing operation mode and power consumption is reduced compared withthe time of the DSP normal operation mode. After executing Step S4, theMPU 3 returns to the waiting state.

If the DSP reducing signal is transmitted by the CPU 4, the applicationwhich needs the state information 11 is ended and the CPU 4 can considerthat the state information 11 is not needed henceforth. In such a case,the state estimation system 1 reduces power consumption further bystopping sensing by the sensor 2.

After executing Step S3, it is not necessary to read the output of thesensor 2. Therefore, the MPU 3 (the switching section 306) may stop thetimer 32. In Step S3, the state estimation system 1 (the MPU 3) may notstop all the sensors 2, and it may select the sensor to stop accordingto a situation.

On the other hand, when the origin of the transmission of the DSPreducing signal is not the CPU 4 (No in Step S2), the MPU 3 skips StepS3 and executes Step S4. Therefore, henceforth, the DSP 30 becomes theDSP reducing operation mode and returns to the waiting state.

If the DSP reducing signal is not transmitted by the CPU 4, it can beconsidered that the CPU 4 needs the state information 11. Therefore, asfor sensing by the sensor 2, it is preferable to make it continue inthis case, without stopping the sensor 2.

The case where the origin of the transmission of the DSP reducing signalis not the CPU 4, the case where the sensor 2 becomes a transmittingagency, the case where the DSP 30 the very thing tends to switch oneselfin the DSP reducing operation mode, etc. are assumed.

In the waiting state, when the detection timing has come (Yes in StepS5), the timer 32 outputs the detection timing signal, as an interruptsignal, towards the DSP 30 (Step S6). According to this, the MPU 3 readsthe output of each sensor 2 (Step S7). In this manner, the detectioninformation 10 is stored in the RAM 31.

Next, the MPU 3 compares the output value of the sensor 2 read in StepS7 with the output value of the sensor 2 read when Step S7 was performedlast time, and it judges whether the difference is below a thresholdvalue (Step S8).

The case where the difference is below the threshold value is a case inwhich the change in a state is scarce. Therefore, when the MPU 3 givesYes as the result in Step S8, the MPU 3 further judges whether such astate continues during a predetermined period (Step S9).

When the MPU 3 gives Yes as the result in Step S9, the MPU 3 notifiesthe CPU 4 that the state does not have a change (Step S10). And whenStep S10 is executed, the switching section 306 shifts the DSP 30 to theDSP reducing operation mode (Step S4).

Thus, when the scarce state of the change continues during apredetermined period in the detection information 10, the stateestimation system 1 can reduce power consumption by switching the DSP 30to the DSP reducing operation mode. It can be constituted so that eachsensor 2 judges whether a change is scarce in the detection information10. In this case, it can be constituted so that each sensor 2 transmitsthe judgment together with the detection information 10 to the MPU 3.

On the other hand, when it is No in Step S8 or S9, the MPU 3 returns tothe waiting state, without executing Step S10.

In the waiting state, when the DSP wake-up signal is received (Yes inStep S11), the switching section 306 switches operational mode of theDSP 30 to the DSP normal operation mode (Step S12). Therefore, the DSP30 returns to the DSP normal operation mode.

When Step S12 is executed, the MPU 3 decides whether the sensor 2 isunder stop (Step S13). And when the stopped sensor 2 exists, the MPU 3starts the stopped sensor 2 (Step S14). Thus, the stopped sensor 2returns. When the decision result is No in Step S13 or Step S14 isexecuted, the MPU 3 returns to the waiting state.

In the waiting state, when the operation timing has come (Yes in StepS15), the DSP 30 executes a predetermined operation, estimates theuser's condition, and generates the state information 11 (Step S16). Thearrival of the operation timing establishes the exclusive timer in theMPU 3 and may be decided periodically. The arrival of the operationtiming may be decided by the fact that the CPU 4 requests to output thestate information 11.

The state information 11 is stored in the RAM 31 by execution of StepS16. When the decision result is Yes in Step S15 and the DSP 30 is inthe DSP reducing operation mode, the switching section 306 switches theDSP 30 to the DSP normal operation mode before Step S16 is executed.

When Step S16 is executed, the MPU 3 (the interface part 33) outputs thenewly created state information 11 to the CPU 4 (Step S17).

The CPU 4 receives the state information 11 by execution of Step S17.Therefore, the CPU 4 which received the state information 11 creates theoutput information 12 based on the received state information 11. Whenexecuting Step S17, in the case where operational mode of the CPU 4 isthe CPU reducing operation mode, before executing Step S17, the MPU 3outputs the CPU wake-up signal to the CPU 4.

When Step S17 is executed, the switching section 306 switchesoperational mode of the DSP 30 to the DSP reducing operation mode once(Step S18).

Thus, whenever the MPU 3 completes the output of the new stateinformation 11, the switching section 306 makes the DSP 30 shift to theDSP reducing operation mode. Therefore, power consumption is reducedfurther.

When Step S18 is executed, the MPU 3 returns to the waiting state.

As mentioned above, the MPU 3 has the interface part 33 obtains thedetection information 10 obtained by the sensor 2 and outputs the stateinformation 11 to the CPU 4, and the DSP 30 has the arithmetic logicunit 304 is constituted as a SIMD type computing unit provided with thefour single precision floating point computing units 305. The DSP 30processes a plurality of information by one command. The DSP 30estimates the state of the object based on the detection information 10obtained by the interface part 33, and generates the state information11 according to the state of the object. Thereby, the MPU 3 can lowerthe frequency of the DSP 30. Additionally, the MPU 3 can make circuitstructure small compared with the case where a fixed-point arithmeticmachine is adopted. Therefore, power consumption can be reduced.

The DSP 30 estimates the state of the object using the Kalman filter tothe detection information 10, and generating the state information 11.That is, the DSP 30 produces a still higher effect compared with aprocessor provided with a fixed-point arithmetic machine.

The DSP 30 processes 6-axes or more (preferably 9-axes or more, and morepreferably 12-axes or more) of information in parallel based on thedetection information 10. Thus, a still higher effect is produced byprocessing the information about the multiple spindle which occurssimultaneously.

The MPU 3 further has the switching section 306 switches operationalmode of the DSP 30 between the DSP normal operation mode and the DSPreducing operation mode. The DSP reducing operation mode is operationalmode in which power consumption is smaller than the DSP normal operationmode. The DSP 30 generates the state information 11 in the DSP normaloperation mode. Thereby, in the period which does not generate the stateinformation 11 for example, operational mode can be switched in the DSPreducing operation mode, and power consumption can be reduced further.

The switching section 306 switches operational mode between the normaloperation mode and the reducing operation mode according to the demandfrom the CPU 4. Thereby, the MPU 3 can be used according to the startingapplication, for example. Therefore, the MPU 3 can be used efficiently.

According to the demand (the DSP wake-up signal) from the CPU 4, the MPU3 changes from the DSP reducing operation mode to the DSP normaloperation mode and starts the sensor 2. In this manner, when the CPU 4desires the information, the MPU 3 starts the sensor 2 beforehand andcan change into the state where the detection information 10 isacquirable.

The switching section 306 switches operational mode of the DSP 30between the DSP normal operation mode and the DSP reducing operationmode according to the detection information 10 from the sensor 2.Especially, the switching section 306 switches the operational mode tothe DSP reducing operation mode, when the state where the change in thedetection information 10 from the sensor 2 has become below thethreshold value continues for a predetermined period. In this manner,when a possibility that the state of the object turned into a stationarystate is high, the switching section 306 switches operational mode tothe DSP reducing operation mode in which power consumption is low.Therefore, power consumption can be reduced.

When the DSP 30 is in the DSP reducing operation mode and the change inthe detection information 10 from the sensor 2 changes into a largerstate than the threshold value, the switching section 306 switchesoperational mode of the DSP 30 to the DSP normal operation mode with theDSP wake-up signal from the sensor 2. Thus, when a possibility that thestate of the object changed is high, the DSP 30 shifts to the DSP normaloperation mode promptly and estimates the state of the object.Therefore, change of the state of the object can be promptly notified tothe CPU 4.

As mentioned above, although described about the preferred embodiment ofthe invention, the present invention is not limited to the abovementioned embodiment, and various deformation is possible for it.

For example, the steps shown in the preferred embodiment are mereexamples. The steps are not limited to the order and the contentsdescribed above. That is, if the same effect can be obtained, the orderor the contents may be modified as appropriate. For example, when StepS7 is performed and the new detection information 10 is stored in theRAM 31, the MPU 3 may generate the state information 11 by executingStep S16, and may output the state information 11 by executing Step S17.

The single precision floating point computing unit 305 is adopted forexample in the above preferred embodiment, it may not be limited to“single-precision”. A double-precision-floating-point computing unit maybe adopted, for example.

Further, for example, the timer which determines the timing whichreturns the DSP 30 to the DSP normal operation mode from the DSPreducing operation mode, may be provided. When such a timer is providedand the DSP 30 returns to the DSP normal operation mode by the timer,and when the change in the detection information 10 from the sensor 2 isbelow the threshold value, the interface part 33 may output theinformation in which indicates that there is no change of the state ofthe object, towards the CPU 4. And in this case, the switching section306 may make the DSP 30 shift to the DSP reducing operation mode. Inthis manner, creation of the state information 11 by the DSP 30 can beavoided, and it can shift to the DSP reducing operation mode in a shorttime compared with the case where the new state information 11 isgenerated. It is effective especially in a case when CPU 4 is demandingthe state information 11 periodically and when no change will be in astate.

During the CPU reducing operation mode and when it can be consideredthat there is no change of a state of an object, the interface part maybe forbidden from outputting the information (the state information 11,the information which indicates there is no change of the state of theobject) to the CPU 4. In this manner, the useless start of the CPU 4 iscontrolled and the power consumption is more reduced.

In addition, the MPU 3 is provided with the user interface and astructure in which a liquid crystal panel is connected with the MPU 3may be adopted.

In the above preferred embodiment, an example is described in which theuser is the object and the state of the user is estimated. However, theobject may not be limited to the user and may be portable terminaldevice (state estimation system 1), for example. In this case, anattitude, a state of rest, or portable states (a gesture, fixing, etc.)are assumed to be the states where it is estimated.

While the invention has been shown and described in detail, theforegoing description is in all aspects illustrative and notrestrictive. It is therefore understood that numerous modifications andvariations can be devised without departing from the scope of theinvention. The scope of the present invention is shown by claims.

What is claimed is:
 1. A state estimation processor connected to anexternal detection device and an external computer, comprising:interface circuitry configured to obtain detection information obtainedby the external detection device and output state information to theexternal computer; calculating circuitry including a SIMD typearithmetic processing circuitry processes a plurality of information byone command and provided with at least four single precision floatingpoint computing circuits, the one command being executed in parallel toa plurality of data set to each of the at least four single precisionfloating point computing circuits in a single cycle; the calculatingcircuitry configured to: estimate a state of an object based on thedetection information obtained by the interface circuitry; generate thestate information according to the state of the object; compare firstdetection information received at a first point in time with seconddetection information received at a second point in time, which issubsequent to the first point in time; control the interface circuitryto output a notification to the external computer when it is determinedthat a difference between the first detection information and the seconddetection information is less than a predetermined threshold value; andswitch an operational mode from a first operation mode, during which thestate information is generated, to a second operation mode in whichpower consumption is smaller than the first operation mode aftercontrolling the interface circuitry to output the notification to theexternal computer.
 2. The state estimation processor according to claim1, wherein the calculating circuitry configured to estimate the state ofthe object using a Kalman filter to the detection information, andgenerates the state information.
 3. The state estimation processoraccording to claim 1, wherein the calculating circuitry configured toprocesses 6 or more axes information in parallel based on the detectioninformation.
 4. The state estimation processor according to claim 3,wherein the calculating circuitry configured to processes 9 or more axesinformation in parallel based on the detection information.
 5. The stateestimation processor according to claim 4, wherein the calculatingcircuitry configured to processes 12 or more axes information inparallel based on the detection information.
 6. A state estimationsystem, comprising: a detection device obtains detection information; amain processor works in first operation mode, and second operation modein which power consumption is smaller than the first operation mode; anda state estimation processor connected to the detection device and themain processor; wherein the state estimation processor, including: aninterface circuitry configured to obtain detection information obtainedby the detection device and output state information to the mainprocessor; and a calculating circuitry including a SIMD type arithmeticprocessing circuitry processes a plurality of information with onecommand and provided with a single precision floating point computingunit; the calculating circuitry configured to: estimate a state of anobject based on the detection information obtained by the interfacecircuitry; and generate the state information according to the state ofthe object; the main processor configured to: shift to the firstoperation mode based on a timing which the state information is inputfrom the interface circuitry; generate output information during thefirst operation mode based on the state information generated by thestate estimation processor.
 7. The state estimation system according toclaim 6, wherein the state estimation processor, further comprising: aswitching circuitry configured to switch operational mode of thecalculating circuitry between third operation mode and fourth operationmode in which power consumption is smaller than the third operationmode.
 8. The state estimation system according to claim 7, wherein theswitching circuitry configured to switch operational mode of thecalculating circuitry between third operation mode and fourth operationmode according to a demand from the main processor.
 9. The stateestimation system according to claim 8, wherein the state estimationprocessor starts the detection device when the calculating circuitrychanges from the fourth operation mode to the third operation modeaccording to a demand from the main processor.
 10. The state estimationsystem according to claim 7, wherein the switching circuitry configuredto switch operational mode of the calculating circuitry between thethird operation mode and the fourth operation mode according to thedetection information from the detection device.
 11. The stateestimation system according to claim 10, wherein the switching circuitryconfigured to switch to the fourth operation mode when the state wherechange in detection information from the detection device has becomebelow a threshold value continues at a predetermined period.
 12. Thestate estimation system according to claim 11, further comprising: atimer determines timing in which the calculating circuitry returns tothe third operation mode from the fourth operation mode; wherein in acase where the calculating circuitry returns to the third operation modewith the timer, and also in a case where the change in the detectioninformation from the detection device is below a threshold value, theinterface circuitry configured to output that the state of the objectdoes not have a change for the main processor, and the switchingcircuitry configured to switch the calculating circuitry to the fourthoperation mode.
 13. The state estimation system according to claim 12,wherein in a case where the main processor is in the second operationmode, the interface circuitry configured to prohibit from outputtingthat the state of the object does not have a change.
 14. The stateestimation system according to claim 10, wherein in a case whereoperational mode of the calculating circuitry is the fourth operationmode, and also in a case where a change in the detection informationfrom the detection device changes into a larger state than a thresholdvalue, the switching circuitry configured to switch the calculatingcircuitry to the third operation mode.